Facebook has, until recently, been a place where you shout about what you are doing; whereby friends will invariably reply by shouting back:"I did this" or "I did that". However, with everyone wanting a piece of the BlackBerry BBM pie and Apple about to launch its own messaging service - iMessage - Facebook now wants you to use its social network as the place of choice when it comes to arranging that visit to the cinema or, more likely, the pub.

Facebook Messenger

For iPhone customers the Facebook Messenger app is only available in the US iTunes store, and as yet is not available in the UK. That's likely to change of course, and playing with the US version we've seen nothing location specific to imply that it won't be coming to the UK. Still, at the time of writing, that's why you can't find it in the UK iTunes store if you look. It appears to be the same with the Android version too.

The app has been designed for the iPhone and the iPhone's 3.5-inch screen. It will work on the iPad, but it's not iPad friendly, which is disappointing - Facebook clearly didn't believe that you'd wanted to use the Apple tablet to message people.

Punch in your login details, and you're connected. The app runs in the background and you can opt to have notifications either turned on or off, to alert you when you do in fact get a message.

Taking the settings one step further you can set individual rules for conversations in question or all conversations in general.

Those rules are really about the alerts you get and it's a nice touch that they are time-specific, as well as just "yes to alerts" or "no to alerts".

That means you can say - "Alerts off for 1 hour" or "Alerts off until 8:00am". Sadly you can't change these timing options.

The boring settings out of the way, what of the messaging side of things? Signing in gives you a list of all the messages you've ever had with anyone on the main website Facebook Messenger. It's rather scary to know that the site has kept all these messages all this time (we were shown ones from over a year ago), but it does mean that you can pick up where you left off - "yes we really are over."

Clicking on the "compose message" icon gives you the message page and the ability to decide who to message. Start typing a friends name and the app automatically pulls in a list of people that match that letter/word from your Facebook contacts. Typing "Rich", for example, showed me that I had four friends called Richard and clicking on the right one brought that contact into the "To" box.

A quick message later and we were talking just like we would on the messaging service on Facebook - or BBM and iMessage (iOS 5) for that matter. A look at the Facebook website and the conversation has been recorded there too, giving you a fluid chat experience.

Aside from chat messages you can send your location, which the other person can then use to find you in the pub, as the app automatically loads in Google maps (which you have zooming control over). We expect it to be a handy feature.

With notifications on the iPhone about to get better thanks to iOS5 and an always-on status, this catapults Facebook into the messaging game 100 per cent.

Some will question why you need a dedicated messaging app, but having used it for the morning it's clear to see why. Facebook is trying to get you from just shouting about what you are doing, to becoming a service that allows you to arrange and organise what you are doing - that means more people using the service more of the time.

It also means that once you've arranged where to meet chances are you'll then use the full Facebook app to share what you did with your friends - thereby completing the circle.

The beauty is, unlike other messaging services, all your friends are likely to be there already.